1. Field of the Invention
The present invention relates to the handling of hazardous waste. More specifically, the present invention relates to portable, reusable containers in which liquid material for use with oil or gas drilling equipment can be circulated during use, and wastes therefrom can be temporarily stored for later disposal after use.
2. Prior Art
Oil and gas drilling operations produce drill cuttings or "tailings" that consist of material removed from a well, with mixtures of other liquids and materials that are used to facilitate drilling. These materials are generally unwanted by products once the drilling process is completed, and are a present or potential danger to the health of humans or other living organisms because they often exhibit undesirable properties such as toxicity, carcinogenicity, non-degradeability, biological magnification or the like. With present technology, a wide variety of useful products cannot be manufactured without also producing some hazardous waste. It is not presently possible to recycle all of the waste, so safe means of handling and disposal must be found.
As awareness of the dangers of air and water pollution has increased, methods of disposing of waste into the air, such as by burning, and into rivers or oceans, have been recognized as being undesirable in many situations. Legislation and regulations strictly limit such disposal methods in the United States and in many other countries.
As the disposal of hazardous wastes into the air and water has been reduced, there naturally has been an increase in the amount of disposal on land. One method has been to bury the wastes in a landfill. For example, one method is to pump the waste back into the well after the drilling operation has been completed. Another method, used especially for wastes including the tailings, spent drilling liquids, and other materials such as drilling "mud" type wastes resulting from a drilling operation is to pump the waste into open surface pits for storage. Since it is necessary to dig an open surface, or ground pit, to hold and circulate the large volume of fluids used and generated during the drilling process, it has often been most cost effective to leave the waste liquid in this same pit which was made and used during the drilling operation. This resulted in hazardous waste ground pits being located in numerous places which were often relatively unsuitable, instead of being brought to a more central, safe and suitable storage location.
In many land-based disposal sites, the prevention of waste from contaminating the ground water supply is a major concern. Therefore, ground pits which are dug for the purpose of storing the drilling fluids must be provided with a liner, such as a plastic material, which prevents leakage of the liquid into the soil. When this type of ground pit is used for long term storage of the liquids however, it entails numerous drawbacks. These drawbacks include: the impossibility of making a visual check on the wastes and on their progress; the great difficulty and the high cost of taking samples for the periodic analysis that are normally necessary; the difficult problem raised by the need for quantitative and qualitative follow-up measures; the signs of the changes undergone by the stored wastes, such as leaching of liquid into the soil; the presence of malodorous or even explosive gases; the need, when the discharge produces intolerable pollution, to remove the stored wastes and process them elsewhere, which leads to difficult and extremely costly operations; and finally, the understandable climate of suspicion that grows among the surrounding populous. It is therefore an imperative and pressing need for storage systems for fluids used in the drilling process which avoid the need to dig expensive ground pits, and which facilitate removal of the waste fluids after the drilling operation is completed to a suitable waste collection and storage facility.
Further, as public awareness of hazardous waste has increased, it has been necessary to clean up the ground pit waste storage sites which have become unsatisfactory. Although the "Superfund" program in the United States has helped in the recovery of hundreds of hazardous waste sites which have already been identified in which waste is not now safely stored, there is nevertheless a large expense involved to the drilling companies in reclaiming unsatisfactory ground pit sites. Also, the increased public and scientific concern about hazardous waste has drastically slowed the opening of new landfills and increased the regulations for proper digging of new ground pits. Proposing the digging of a new ground pit for a main landfill site raises difficult political as well as technological questions, which are often addressed in regulatory proceedings which can be very lengthy.
Therefore, at a time when the demand for environmentally sound disposal facilities is large, and the supply of such facilities has been sharply limited, any procedure that would permit the optimal use of each satisfactory collection site, and avoid the need for the use of ground pits at each individual drilling site, would be a tremendous benefit. Further, any such improved procedure which allows the saving of time and expense in the drilling procedure, and which would be reusable for numerous different drilling operations, would be an added significant benefit.
The present invention is an improvement in hazardous waste storage technology which can help solve the above enumerated problems presently existing with the storage and handling of drilling fluids.